/*

* Copyright (c) 2004 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  This interface defines a generic data type

*

*/

#ifndef I_ALFMODELCHANGEOBSERVER_H

#define I_ALFMODELCHANGEOBSERVER_H

//INCLUDES

namespace osncore

    {

template <class T> class AlfPtrVector;

    }

using namespace osncore;

namespace Alf

    {

/* Forward declarations*/

class IAlfModel;

class AlfModelOperation;

/**

*  An interface for observing the changes in the model.

*  @lib hitchcockwidgetmodel.lib

*  @since S60 ?S60_version

* @status Draft

*/

class IAlfModelChangeObserver

    {

public:

    /** Virtual destructor.*/

    virtual ~IAlfModelChangeObserver() {}

    /**

     * Notify the observer that the model has changed.

     *

     * @param aModel    The new model.

     * @since S60 ?S60_version

     */

    virtual void modelChanged( IAlfModel& aModel ) = 0;

    /**

     * Notify the observers that a number of change operations

     * are about to be performed on the model.

     *

     * @param aArrayOfOperation An Array containing the operations performed on the model.

     * @since S60 ?S60_version

     */

    virtual void dataChanging( const AlfPtrVector<AlfModelOperation>& aArrayOfOperation ) = 0;

    /**

     * Notify the observers that a change operation

     * is about to be performed on the model.

     *

     * @param aOperation    An operation performed on the model.

     * @since S60 ?S60_version

     */

    virtual void dataChanging( const AlfModelOperation& aOperation ) = 0;

    /**

     * Notify the observers that the data of the model has been changed.

     * This is called automatically after any DataChangingL() call.

     *

     * @since S60 ?S60_version

     */

    virtual void dataChanged() = 0;

    };

    } // namespace Alf

#endif // I_ALFMODELCHANGEOBSERVER_H

// End of File